In this image posted by @JonnyKimUSA via X on July 14, 2025, astronaut Shubhanshu Shukla with crew members of the Axiom-4 mission and International Space Station (ISS). After 18 days of intense science experiments at the ISS, it is time for farewells and feasts for Shubhanshu Shukla and three other astronauts of the Axiom-4 mission who are set to begin their return journey to Earth on Monday.
Credit: PTI Photo
New Delhi: Astronaut Shubhanshu Shukla, the Axiom-4 mission pilot, has showcased a zero-gravity experiment aboard the International Space Station (ISS) involving water to illustrate how microgravity transforms everyday physics.
The experiment, part of Axiom Space's outreach and scientific mission, highlighted the unique behaviour of water in space.
After an 18-day stay at the ISS, Shukla and three others -- commander Peggy Whitson and mission specialists Slawosz Uznanski-Wisniewski of Poland and Tibor Kapu of Hungary -- of the commercial Axiom-4 mission set off on a return journey to Earth on Monday evening.
Using surface tension to their advantage, Shukla formed a floating water bubble.
"I've become a water bender here in the station," he joked.
Another astronaut, Whitson, further went on to press a plastic bag gently into the sphere, demonstrating how surface tension behaves like a magnet in microgravity by clinging to the object and distorting light like a lens.
The astronauts also spoke about the opportunity not just to engage in science but also to communicate the wonder and beauty of Earth from space.
"I try to savour every moment I get -- just sitting by the window and looking down. It's the most beautiful view I've seen," Shukla said onboard the ISS.
Whitson explained that the crew is nearing the end of their two-week mission, during which they've balanced rigorous scientific research with education and public engagement.
Their mission has also included outreach to students and STEM communities around the globe, including in India, Hungary, and Poland.
Asked about re-entering Earth's gravity, Whitson was frank: "From me having experienced it, I know first person -- it sucks. Gravity really does." Shukla, on his maiden spaceflight, said he hopes to handle the descent better than his ascent, which involved some space motion sickness.
In the final leg of his space sojourn, Shukla turned into a farmer, taking photos of 'moong' and 'methi' seeds sprouting in petri dishes and inserting them into a storage freezer on the International Space Station (ISS) as part of a study on how microgravity influences germination and early plant development.
"I am so proud that ISRO has been able to collaborate with national institutions all over the country and come up with some fantastic research which I am doing on the station for all the scientists and researchers. It is exciting and a joy to do this," Shukla said in an interaction with Axiom Space Chief Scientist Lucie Low on June 9.
The sprouts experiment is led by two scientists -- Ravikumar Hosamani of the University of Agricultural Sciences, Dharwad and Sudheer Siddapureddy of the Indian Institute of Technology, Dharwad.
Once returned to Earth, the seeds will be cultivated over several generations to examine changes in their genetics, microbial ecosystems and nutritional profiles, a statement from Axiom Space said.
In another experiment, Shukla deployed and stowed microalgae, which are being investigated for their potential to produce food, oxygen and even biofuels. Their resilience and versatility make them ideal for supporting human life on long-duration missions.
Shukla also captured images for the crop seeds experiment, where six varieties will be grown over multiple generations post-mission. The goal is to identify plants with desirable traits for genetic analysis for sustainable farming in space.
Shukla said his research tasks on the space station spanned various domains and disciplines.
"Right from doing stem cell research and looking at the effect of microgravity on seeds, evaluating the cognitive load on astronauts while they are interacting with screens onboard the station. It has been fantastic. I feel proud to be this kind of a bridge between the researchers and the station and do the research on behalf of them," he said last week.
"One particular research I am really excited about is stem cell research where scientists are trying to explore whether it is possible to accelerate recovery or growth or repair injury by adding supplements to stem cells. It has been great to work in the Glove Box doing this research for them. I am really excited to be doing this," Shukla said.
Science and Technology Minister Jitendra Singh on Monday said the experiments carried out by Shukla related to life sciences and other fields were supported by indigenous kits.
"As the Prime Minister says 'Vasudhaiva Kutumbakam' - the world is one family - the benefits of all these experiments done by an Indian using indigenous kits will benefit the entire world," Singh told reporters on the sidelines of a consultative meeting on ease of doing research and development held at IIT Jammu.
"The most important point is that the experiments conducted by Shubhanshu used kits provided by the Institute of Biotechnology and the Indian Institute of Science and IIT.
"This means we used indigenous kits, conducted indigenous experiments, and had an Indian astronaut carrying them out. These are experiments whose benefits will also be shared with other countries," he said.
He said the experiments carried out in space were based on concepts that had not been imagined until now, and Shubhanshu Shukla is the first Indian to have conducted them.
"In life sciences, one of the experiments involved studying the effect of space on muscles, since in space, muscle dysfunction and wasting occur, and how that can be prevented.
"Another experiment examined the cognitive effects of using gadgets over the long term in space, and what kind of impact this could have on the heart and brain, and how those effects can be mitigated," he said.